The present invention relates broadly to a gasket for sealing between the cylinder head and block of an internal combustion engine, and particularly to a gasket construction including elastomeric members attached to a metal retainer for sealing about the fluid port openings of the engine.
Head gaskets are employed in internal combustion engines as interposed for compression between the mating surfaces of the cylinder head and block for effecting the fluid-tight sealing thereof. In basic construction, gaskets of such type are conventionally constructed of a generally planar member formed of one or more layers of fiberboard, graphite, and/or a metallic material such as copper, steel, aluminum, or the like. Within the planar member are formed a plurality of apertures for registration with the corresponding bores and fluid passageways of the cylinder head and block. A circular fire or combustion ring formed of a metal wire or the like typically is provided about the circumference of the cylinder bores for effecting a combustion seal.
For example, Meyers et al., U.S. Pat. No. 3,473,813, discloses a cylinder head gasket which includes a metal plate having cylinder bore, lubricating port, and coolant port openings. Elastomeric seals are seated for retention within the lubricating and fluid port openings. The location and size of each of the seals is such that the internal diameter thereof corresponds to and registers with its associated port opening. Concentric fire rings, each formed of a one-piece steel wire clad with a non-ferrous material, are located within each of the cylinder openings.
Fujikawa et al., U.S. Pat. No. 4,272,085, discloses another cylinder head gasket which includes a metal plate having coolant port openings about the peripheries of which an elastomeric seal ring is bonded. Corrugations are formed within the plate about the peripheries of the cylinder bore openings to improve the compressive sealing thereof.
European Patent No. 499,551 discloses another cylinder head gasket formed of a metal core having coolant and lubricant openings which are sealed with an elastomeric ring. A series of ribs and grooves are formed about the peripheries of the cylinder bore openings.
Kitagawa, U.S. Pat. No. 4,915,398, discloses a cylinder head gasket formed of a metallic plate. The plate includes embossments formed around the cylinder bore openings which are deformable under compression for equalizing the forces acting thereon. Udagawa, U.S. Pat. No. 5,439,234, discloses another metal head gasket having sealing beads or corrugations which are integrally-formed around the cylinder bore and fluid port openings thereof.
Pecina, U.S. Pat. No. 5,374,069, discloses a cylinder head gasket formed of an aluminum core faced with upper and lower layers of an elastomeric material. The material is a blend of a synthetic elastomer such as rubber or silicone and a filler such as aramid fibers or clay.
Kubouchi et al., U.S. Pat. No. 5,516,124, discloses a head gasket formed of an elastic metal plate. Beads are formed about the cylinder bores for equalizing the face-to-face pressure in the vicinity thereof.
Czernik et al., U.S. Pat. No. 4,331,336 discloses a cylinder head gasket formed of a multi-layered plate having cylinder bore openings bounded by circular wire fire rings. The plate is a laminate of a central metallic core interposed between outer sheets of an impregnated or elastomeric asbestos material. The gasket is recompressed prior to its installation in an engine. Gaskets of such type, as well as other metal, rubber, and fiber gaskets, are marketed commercially by Fel-Pro Inc., of Skokie, Ill.
Plunkett et al., U.S. Pat. No. 5,490,681 discloses a multi-layered gasket comprising an inner plate interposed between a pair of outer plates. The outer plates are shaped to form sealing beads about the cylinder bore and fluid port openings thereof. The inner plate is shaped to form a flange which provides a combustion seal about the cylinder bore openings.
Copper head gaskets marketed commercially by Mr. Gasket of Cleveland, Ohio, and by Milodon, Inc., of Chatsworth, Calif. A gasket having a molybdenumpolytetrafluoroethylene coating and a wire combustion seal is marketed by FP Diesel L.P., Huntington Beach, Calif. Another gasket including a graphite-faced steel core, stainless steel fire rings, a silicone outer coating, and sealing beads is marked by ROL Mfg., of Quebec, Canada.
The above-described references heretofore have constituted the state of the art with respect to cylinder head gaskets. It will be appreciated, however, that continued improvements in such gaskets would be well-received by the automotive industry for use as original and replacement equipment in passenger cars, and by enthusiasts for use in racing and other high performance applications. A preferred gasket construction would be economical to manufacture, but would exhibit excellent sealing with a minimum of compression set. Such a gasket additionally would be capable of withstanding prolonged exposure to high temperatures as well as to hydrocarbons and other fluids within the rigorous service environment of an internal combustion engine.